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Causes of driver fatigue and how to spot the most common signs

Driver fatigue is a common danger for long-haul drivers. Driving while exhausted significantly increases the risk of a crash – it makes us less aware of what is happening on the road and impairs our ability to respond quickly and safely if a dangerous situation arises. In fact, it is believed to contribute to 30% of road crashes. That’s one out of every three road accidents.

What causes driver fatigue?

There are a few major causes of driver fatigue:

A lack of quality/quantity of sleep

Driving at times of the day during which you’d normally be sleeping

The consequence of both of these is a build-up of sleep debt. This is essentially sleep you ‘owe’ yourself. The only way to repay this debt is to sleep. Until you re-establish a pattern of regular and sufficient sleep, you are more likely to be at risk of being involved in a fatigue-related accident.

4 groups most at risk of driver fatigue

Young drivers: The combination of inexperience and night driving

Shift workers and those working extended hours: Shift workers are six times more likely to be in a fatigue-related crash, whether at work (operating machinery or vehicles) or while commuting

Commercial drivers: Long distance driving, often at night

Business travellers: Drivers suffering from jet lag and crossing time zones often suffer from restricted and/or poor quality sleep

6 factors that will increase the likelihood of driver fatigue

The length of time you’ve been awake (especially if it’s more than 17 hours)

The time of day: Your body and brain have a biological clock (circadian rhythm), which influences how alert or drowsy you are at certain times of the day

The quantity and quality of your last bout of sleep

Your level of physical or mental activity at the time (e.g. long, boring stretches of road make it difficult to maintain alertness and vigilance)

It is very difficult for drivers to accurately assess their own level of fatigue. The ability to self-assess becomes increasingly impaired as you get more fatigued. If you, or your drivers, notice any of the following signs, you must stop and rest.